Factory fit leisure battery Crafter

[Wanderingmac]

Have new Crafter with factory fit second battery which is in the engine compartment. Starter battery is under the floor in front of double passenger seat. Under the double seat is a fuse box and heavy guage battery wires. Does anyone know if these are for leisure battery or engine battery? If they were for leisure battery I could perhaps link into them for power from solar panels. Also is there any easily accessible route to get solar cables from rear of van into the engine compartment without stripping most of front of van? Any help much appreciated.